git.distorted.org.uk Git - u/mdw/putty/blob - windows/wincons.c

   1 /*
   2  * console.c: various interactive-prompt routines shared between
   3  * the Windows console PuTTY tools
   4  */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <stdarg.h>
   9
  10 #include "putty.h"
  11 #include "storage.h"
  12 #include "ssh.h"
  13
  14 int console_batch_mode = FALSE;
  15
  16 static void *console_logctx = NULL;
  17
  18 /*
  19  * Clean up and exit.
  20  */
  21 void cleanup_exit(int code)
  22 {
  23     /*
  24      * Clean up.
  25      */
  26     sk_cleanup();
  27
  28     random_save_seed();
  29 #ifdef MSCRYPTOAPI
  30     crypto_wrapup();
  31 #endif
  32
  33     exit(code);
  34 }
  35
  36 void set_busy_status(void *frontend, int status)
  37 {
  38 }
  39
  40 void notify_remote_exit(void *frontend)
  41 {
  42 }
  43
  44 void timer_change_notify(long next)
  45 {
  46 }
  47
  48 void verify_ssh_host_key(void *frontend, char *host, int port, char *keytype,
  49                          char *keystr, char *fingerprint)
  50 {
  51     int ret;
  52     HANDLE hin;
  53     DWORD savemode, i;
  54
  55     static const char absentmsg_batch[] =
  56         "The server's host key is not cached in the registry. You\n"
  57         "have no guarantee that the server is the computer you\n"
  58         "think it is.\n"
  59         "The server's %s key fingerprint is:\n"
  60         "%s\n"
  61         "Connection abandoned.\n";
  62     static const char absentmsg[] =
  63         "The server's host key is not cached in the registry. You\n"
  64         "have no guarantee that the server is the computer you\n"
  65         "think it is.\n"
  66         "The server's %s key fingerprint is:\n"
  67         "%s\n"
  68         "If you trust this host, enter \"y\" to add the key to\n"
  69         "PuTTY's cache and carry on connecting.\n"
  70         "If you want to carry on connecting just once, without\n"
  71         "adding the key to the cache, enter \"n\".\n"
  72         "If you do not trust this host, press Return to abandon the\n"
  73         "connection.\n"
  74         "Store key in cache? (y/n) ";
  75
  76     static const char wrongmsg_batch[] =
  77         "WARNING - POTENTIAL SECURITY BREACH!\n"
  78         "The server's host key does not match the one PuTTY has\n"
  79         "cached in the registry. This means that either the\n"
  80         "server administrator has changed the host key, or you\n"
  81         "have actually connected to another computer pretending\n"
  82         "to be the server.\n"
  83         "The new %s key fingerprint is:\n"
  84         "%s\n"
  85         "Connection abandoned.\n";
  86     static const char wrongmsg[] =
  87         "WARNING - POTENTIAL SECURITY BREACH!\n"
  88         "The server's host key does not match the one PuTTY has\n"
  89         "cached in the registry. This means that either the\n"
  90         "server administrator has changed the host key, or you\n"
  91         "have actually connected to another computer pretending\n"
  92         "to be the server.\n"
  93         "The new %s key fingerprint is:\n"
  94         "%s\n"
  95         "If you were expecting this change and trust the new key,\n"
  96         "enter \"y\" to update PuTTY's cache and continue connecting.\n"
  97         "If you want to carry on connecting but without updating\n"
  98         "the cache, enter \"n\".\n"
  99         "If you want to abandon the connection completely, press\n"
 100         "Return to cancel. Pressing Return is the ONLY guaranteed\n"
 101         "safe choice.\n"
 102         "Update cached key? (y/n, Return cancels connection) ";
 103
 104     static const char abandoned[] = "Connection abandoned.\n";
 105
 106     char line[32];
 107
 108     /*
 109      * Verify the key against the registry.
 110      */
 111     ret = verify_host_key(host, port, keytype, keystr);
 112
 113     if (ret == 0)                      /* success - key matched OK */
 114         return;
 115
 116     if (ret == 2) {                    /* key was different */
 117         if (console_batch_mode) {
 118             fprintf(stderr, wrongmsg_batch, keytype, fingerprint);
 119             cleanup_exit(1);
 120         }
 121         fprintf(stderr, wrongmsg, keytype, fingerprint);
 122         fflush(stderr);
 123     }
 124     if (ret == 1) {                    /* key was absent */
 125         if (console_batch_mode) {
 126             fprintf(stderr, absentmsg_batch, keytype, fingerprint);
 127             cleanup_exit(1);
 128         }
 129         fprintf(stderr, absentmsg, keytype, fingerprint);
 130         fflush(stderr);
 131     }
 132
 133     hin = GetStdHandle(STD_INPUT_HANDLE);
 134     GetConsoleMode(hin, &savemode);
 135     SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
 136                          ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
 137     ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
 138     SetConsoleMode(hin, savemode);
 139
 140     if (line[0] != '\0' && line[0] != '\r' && line[0] != '\n') {
 141         if (line[0] == 'y' || line[0] == 'Y')
 142             store_host_key(host, port, keytype, keystr);
 143     } else {
 144         fprintf(stderr, abandoned);
 145         cleanup_exit(0);
 146     }
 147 }
 148
 149 void update_specials_menu(void *frontend)
 150 {
 151 }
 152
 153 /*
 154  * Ask whether the selected algorithm is acceptable (since it was
 155  * below the configured 'warn' threshold).
 156  */
 157 void askalg(void *frontend, const char *algtype, const char *algname)
 158 {
 159     HANDLE hin;
 160     DWORD savemode, i;
 161
 162     static const char msg[] =
 163         "The first %s supported by the server is\n"
 164         "%s, which is below the configured warning threshold.\n"
 165         "Continue with connection? (y/n) ";
 166     static const char msg_batch[] =
 167         "The first %s supported by the server is\n"
 168         "%s, which is below the configured warning threshold.\n"
 169         "Connection abandoned.\n";
 170     static const char abandoned[] = "Connection abandoned.\n";
 171
 172     char line[32];
 173
 174     if (console_batch_mode) {
 175         fprintf(stderr, msg_batch, algtype, algname);
 176         cleanup_exit(1);
 177     }
 178
 179     fprintf(stderr, msg, algtype, algname);
 180     fflush(stderr);
 181
 182     hin = GetStdHandle(STD_INPUT_HANDLE);
 183     GetConsoleMode(hin, &savemode);
 184     SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
 185                          ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
 186     ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
 187     SetConsoleMode(hin, savemode);
 188
 189     if (line[0] == 'y' || line[0] == 'Y') {
 190         return;
 191     } else {
 192         fprintf(stderr, abandoned);
 193         cleanup_exit(0);
 194     }
 195 }
 196
 197 /*
 198  * Ask whether to wipe a session log file before writing to it.
 199  * Returns 2 for wipe, 1 for append, 0 for cancel (don't log).
 200  */
 201 int askappend(void *frontend, Filename filename)
 202 {
 203     HANDLE hin;
 204     DWORD savemode, i;
 205
 206     static const char msgtemplate[] =
 207         "The session log file \"%.*s\" already exists.\n"
 208         "You can overwrite it with a new session log,\n"
 209         "append your session log to the end of it,\n"
 210         "or disable session logging for this session.\n"
 211         "Enter \"y\" to wipe the file, \"n\" to append to it,\n"
 212         "or just press Return to disable logging.\n"
 213         "Wipe the log file? (y/n, Return cancels logging) ";
 214
 215     static const char msgtemplate_batch[] =
 216         "The session log file \"%.*s\" already exists.\n"
 217         "Logging will not be enabled.\n";
 218
 219     char line[32];
 220
 221     if (console_batch_mode) {
 222         fprintf(stderr, msgtemplate_batch, FILENAME_MAX, filename.path);
 223         fflush(stderr);
 224         return 0;
 225     }
 226     fprintf(stderr, msgtemplate, FILENAME_MAX, filename.path);
 227     fflush(stderr);
 228
 229     hin = GetStdHandle(STD_INPUT_HANDLE);
 230     GetConsoleMode(hin, &savemode);
 231     SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
 232                          ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
 233     ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
 234     SetConsoleMode(hin, savemode);
 235
 236     if (line[0] == 'y' || line[0] == 'Y')
 237         return 2;
 238     else if (line[0] == 'n' || line[0] == 'N')
 239         return 1;
 240     else
 241         return 0;
 242 }
 243
 244 /*
 245  * Warn about the obsolescent key file format.
 246  *
 247  * Uniquely among these functions, this one does _not_ expect a
 248  * frontend handle. This means that if PuTTY is ported to a
 249  * platform which requires frontend handles, this function will be
 250  * an anomaly. Fortunately, the problem it addresses will not have
 251  * been present on that platform, so it can plausibly be
 252  * implemented as an empty function.
 253  */
 254 void old_keyfile_warning(void)
 255 {
 256     static const char message[] =
 257         "You are loading an SSH 2 private key which has an\n"
 258         "old version of the file format. This means your key\n"
 259         "file is not fully tamperproof. Future versions of\n"
 260         "PuTTY may stop supporting this private key format,\n"
 261         "so we recommend you convert your key to the new\n"
 262         "format.\n"
 263         "\n"
 264         "Once the key is loaded into PuTTYgen, you can perform\n"
 265         "this conversion simply by saving it again.\n";
 266
 267     fputs(message, stderr);
 268 }
 269
 270 void console_provide_logctx(void *logctx)
 271 {
 272     console_logctx = logctx;
 273 }
 274
 275 void logevent(void *frontend, const char *string)
 276 {
 277     if (console_logctx)
 278         log_eventlog(console_logctx, string);
 279 }
 280
 281 int console_get_line(const char *prompt, char *str,
 282                             int maxlen, int is_pw)
 283 {
 284     HANDLE hin, hout;
 285     DWORD savemode, newmode, i;
 286
 287     if (console_batch_mode) {
 288         if (maxlen > 0)
 289             str[0] = '\0';
 290         return 0;
 291     } else {
 292         hin = GetStdHandle(STD_INPUT_HANDLE);
 293         hout = GetStdHandle(STD_OUTPUT_HANDLE);
 294         if (hin == INVALID_HANDLE_VALUE || hout == INVALID_HANDLE_VALUE) {
 295             fprintf(stderr, "Cannot get standard input/output handles\n");
 296             cleanup_exit(1);
 297         }
 298
 299         GetConsoleMode(hin, &savemode);
 300         newmode = savemode | ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT;
 301         if (is_pw)
 302             newmode &= ~ENABLE_ECHO_INPUT;
 303         else
 304             newmode |= ENABLE_ECHO_INPUT;
 305         SetConsoleMode(hin, newmode);
 306
 307         WriteFile(hout, prompt, strlen(prompt), &i, NULL);
 308         ReadFile(hin, str, maxlen - 1, &i, NULL);
 309
 310         SetConsoleMode(hin, savemode);
 311
 312         if ((int) i > maxlen)
 313             i = maxlen - 1;
 314         else
 315             i = i - 2;
 316         str[i] = '\0';
 317
 318         if (is_pw)
 319             WriteFile(hout, "\r\n", 2, &i, NULL);
 320
 321         return 1;
 322     }
 323 }
 324
 325 void frontend_keypress(void *handle)
 326 {
 327     /*
 328      * This is nothing but a stub, in console code.
 329      */
 330     return;
 331 }